So you have a file called test.pl, and somewhere in there is print $ARGV[0]

On the command line, you type perl test.pl hello but you don't get 'hello' written to the command line as you expected.

Some more information would be useful. What does test.pl contain - just the text you indicated, or is that just one line of a file with multiple lines? What OS are you using? You state you don't get hello printed - is anything printed? An error message or notification of some kind? Or do you simply get no output whatsoever?

You might have more luck if you answer some of those questions. Also, take a look at How do I post a question effectively? and the Posting on PerlMonks section of the FAQ (the rest of the FAQ is good, too!); you should be able to get some advice on what you need to include so that you'll be providing enough information so as to make the problem you're having solvable by those who read your node.